The goals of this ongoing project are to evaluate the relationship between clusters of variables encompassing structural (MRI), behavioral (cognitive testing) and metabolic (PET) data associated with Alzheimer's Disease (AD) and Cerebrovascular Disease (CVD) via cross-sectional and longitudinal analyses. Specifically, hippocampal volume (HV) is associated with memory loss, arid both HV and memory loss are related to hypometabolism within the temporal, parietal or posterior cingulate brain regions; all of which are also affected in AD. Additionally, white matter hyperintensities (WMH) are associated with impaired executive performance and frontal lobe hypometabolism; all potentially associated with subcortical CVD. How these clusters of variables are inter-related and their relevance in dissociating CVD from AD are of interest. Therefore, the inter-relationship between alterations in brain structure, function, and metabolism will be evaluated. To investigate their individual metabolic effects, HV, declarative memory, executive function and extent of WMH will be individually covaried with glucose metabolism (PET). Additionally, putative associations between regional hypometabolism, and regional white matter abnormalities will be investigated. Revealing the relationships between these variables associated with CVD and AD may aid in dissociating the two diseases and explaining mechanisms of symptom production. [unreadable] [unreadable]